WPF MVVM WebBrowser dispose - wpf

I am having WebBrowser in my WPF application. I use it for viewing pdf files. But after 50 files are viewed the app throws an exception. So we decided to dispose webbrowser before opening next pdf.
The thing is I do not know how exactly to do that. When I dispose webbrowser it is unbinded and no pdf is viewed anymore. It makes sence, but how to do that correctly?
Here is my code:
public static void BindableSourcePropertyChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
{
WebBrowser browser = o as WebBrowser;
if (browser != null)
{
try
{
browser.Dispose();
browser = null;
browser = new WebBrowser();
}
catch
{
}
string uri = e.NewValue as string;
try
{
if (uri != null)
{
browser.Navigate(new Uri(uri, UriKind.Absolute));
}
}
catch (Exception exception)
{
ExceptionPolicy.HandleException(exception, ExceptionPolicies.General);
}
}
}
And xaml part:
<WebBrowser Grid.Row="0" Behaviour:WebBrowserBehaviour.BindableSource="{Binding WebBrowserData}"
LoadCompleted="WebBrowser_LoadCompleted" />

Basically the problem sounds like you have a memory leak. To help identify it you should use software designed that that purpose. RedAnt has a nice library that I believe has a free trial you can use to help determine what the exact cause of the issue is.
To dispose after loading you can do what is suggested here:
How to dispose of a web browser control after show
But I would suggest you prove that is the problem first by watching the memory or using a tool designed to help detect leaks.

Related

Accessing document elements when using Windows.Forms.WebBrowser

I'm new to automating webpage access, so forgive what is probably a remedial question. I'm using C#/Windows.Forms in a console app. I need to programmatically enter the value of an input on a webpage that I cannot modify and that is running javascript. I have successfully opened the page (triggering WebBrowser.DocumentCompleted). I set browser emulation mode to IE11 (in registry), so scripts run without errors. When DocumentCompleted() triggers, I am unable to access the document elements without first viewing the document content via MessageBox.Show(), which is clearly not acceptable for my unattended app.
What do I need to do so that my document elements are accessbile in an unattended session (so I can remove MessageBox.Show() from the code below)? Details below. Thank you.
The input HTML is:
<input class="input-class" on-keyup="handleKeyPress($key)" type="password">
My DocumentCompleted event handler is:
private static void LoginPageCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
WebBrowser wb = ((WebBrowser)sender);
var document = wb.Document;
// I'm trying to eliminate these 3 lines
var documentAsIHtmlDocument = (mshtml.IHTMLDocument)document.DomDocument;
var content = documentAsIHtmlDocument.documentElement.innerHTML;
MessageBox.Show(content);
String classname = null;
foreach (HtmlElement input in document.GetElementsByTagName("input"))
{
classname = input.GetAttribute("className");
if (classname == "input-class")
{
input.SetAttribute("value", password);
break;
}
}
}
The problem for me was that the page I'm accessing is being created by javascript. Even though documentComplete event was firing, the page was still not completely rendered. I have successfully processed the first page by waiting for the document elements to be available and if not available, doing Application.DoEvents(); in a loop until they are, so I know now that I'm on the right track.
This SO Question helped me: c# WebBrowser- How can I wait for javascript to finish running that runs when the document has finished loading?
Note that checking for DocumentComplete does not accurately indicate the availability of the document elements on a page generated by javascript. I needed to keep checking for the elements and running Application.DoEvents() until they became available (after the javascript generated them).
If the problem comes from the creation of a STAThread, necessary to instantiate the underlying Activex component of WebBrowser control, this is
a modified version of Hans Passant's code as shown in the SO Question you linked.
Tested in a Console project.
class Program
{
static void Main(string[] args)
{
NavigateURI(new Uri("[SomeUri]", UriKind.Absolute), "SomePassword");
Console.ReadLine();
}
private static string SomePassword = "SomePassword";
private static void NavigateURI(Uri url)
{
Thread thread = new Thread(() => {
WebBrowser browser = new WebBrowser();
browser.DocumentCompleted += browser_DocumentCompleted;
browser.Navigate(url);
Application.Run();
});
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
}
protected static void browser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
WebBrowser browser = ((WebBrowser)sender);
if (browser.Url == e.Url)
{
while (browser.ReadyState != WebBrowserReadyState.Complete)
{ Application.DoEvents(); }
HtmlDocument Doc = browser.Document;
if (Doc != null)
{
foreach (HtmlElement input in Doc.GetElementsByTagName("input"))
{
if (input.GetAttribute("type") == "password")
{
input.InnerText = SomePassword;
//Or
//input.SetAttribute("value", SomePassword);
break;
}
}
}
Application.ExitThread();
}
}
}

w8 default tablet settings conflicts with WPF layout

I have a WPF desktop app. I've gotten reports from W8 users that the code completion window in our app is not aligned correctly. I investigated and found out that its a setting in W8 tablet settings that conflicts with the placement of popups in wpf
Default is right handed and then the code completion popup looks like this
When changed to left handed the code completion popup renders correctly like this
Is there a way to programmaticly force the app to use left handed settings, or ignore it completely so it renders like in w7?
edit: Got an upwote so can update with solution, requires .NET 4.5
private static readonly FieldInfo MenuDropAlignmentField;
static MyWindow()
{
MenuDropAlignmentField = typeof (SystemParameters).GetField("_menuDropAlignment",
BindingFlags.NonPublic | BindingFlags.Static);
System.Diagnostics.Debug.Assert(MenuDropAlignmentField != null);
EnsureStandardPopupAlignment();
SystemParameters.StaticPropertyChanged += (s, e) => EnsureStandardPopupAlignment();
}
private static void EnsureStandardPopupAlignment()
{
if (SystemParameters.MenuDropAlignment && MenuDropAlignmentField != null)
{
MenuDropAlignmentField.SetValue(null, false);
}
}
Full code here
https://github.com/AndersMalmgren/FreePIE/blob/master/FreePIE.GUI/Shells/MainShellView.xaml.cs

Launch default web browser, but not if URL already open

I have a link on my app UI that launches a URL using System.Diagnostics.Process.Start(). If the user clicks the link several times, it opens several tabs.
Is there a way, maybe a command-line option, to still use the default web browser, but have it just reopen the same tab if the URL is already open? It would be OK if it doesn't work with every possible browser out there, but nice if it at least works with IE, Firefox and Chrome.
I doubt it, but since I didn't see any other questions/answers on this topic, I figured I'd ask.
This is somewhat of a workaround but it might get you started. I have used the System.Diagnostics.Process.ProcessId.
As an example I have used IE, I will explain later why I did this. The code is just "quick and dirty" but I just made it as proof of concept.
I have created a basic WinForm app with one button that will open google in IE, if it has already been opened by the application it will not be opened again.
I added the System.Diagnostics reference.
public int ProcessID;
public Form1()
{
InitializeComponent();
}
private void MyButton_Click(object sender, EventArgs e)
{
if (ProcessID == null)
{
StartIE();
}
else
{
if (!ProcessIsRunning())
{
StartIE();
}
}
}
private bool ProcessIsRunning()
{
bool ProcessRunning = false;
foreach (Process p in Process.GetProcesses())
{
try
{
if (p.Id == ProcessID)
{
ProcessRunning = true;
}
}
catch { }
}
return ProcessRunning;
}
private void StartIE()
{
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.FileName = "iexplore.exe";
proc.StartInfo.Arguments = "http://www.google.be";
proc.Start();
ProcessID = proc.Id;
}
This does not completely do what you requested but it might be a good start. There are a few reasons why I did it this way and what possible options are..
If you would use the url as the Filename, it would indeed open up the webpage in the default browser, it would however not return a processID. This is why the snippet shows usage of IE. (If you would use this option, you could use the System.IO.File.Exists to make sure the desired browser is installed)
If you would like to use this option, you can query the registry to pick up what te default browser is, if you have that you could launch that from the value obtained from the registry. If you then change the process.startinfo.filename to this value, then you will launch the default browser but you will still obtain a processId so this might be the way forward. You can check how to do this over here: http://social.msdn.microsoft.com/Forums/en/netfxbcl/thread/b200903e-ce69-4bd4-a436-3e20a7632dc4
Showing the internet window if it would already be opened, can be done by using the SetForegroundWindow property. As this is already documented in this article, I did not add it in this snippet.
I hope this helps to get you on your way.

invalid cross-thread access in release

I have a lightswitch application needs to generate Crystal Report from it's WCF Ria. In the development runtime I am able to generate correctly without errors, but when I push it to release environment it prompt error - invalid cross-thread access.
I've read some articles already and it is very likely Silverlight UI Thread problem
partial void GenerateReport_Execute()
{
try
{
GenerateCrystalReport.Load();
var temp = DataWorkspace.QUMCrystalReportDomainData.GenerateCrystalReport(SearchQuery.SelectedItem.GroupId, sQuarter, sYear, eQuarter, eYear);
System.Windows.Deployment.Current.Dispatcher.BeginInvoke(delegate()
{
var uri = new Uri("C:\\Temp\\ReportTest.pdf", UriKind.RelativeOrAbsolute);
if (AutomationFactory.IsAvailable)
{
var shell = AutomationFactory.CreateObject("Shell.Application");
shell.ShellExecute(uri.ToString());
}
else if (!System.Windows.Application.Current.IsRunningOutOfBrowser)
{
HtmlPage.Window.Navigate(uri, "_blank");
}
else
{
throw new InvalidOperationException();
}
});
}
catch ( Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
Am I doing incorrectly? please help me identify this.
Thanks in Advance
Sam
Answering my question, basically that messagebox at bottom is causing the UI problem.
Lightswitch's dispatcher is not same as wpf's dispatcher(what that messagebox uses), please correct if I'm wrong

Is it possible to show/hide UserControls within a Silverlight XAP file from JavaScript?

I've created a Silverlight project that produces [something].xap file to package a few silverlight UserControls. I would like to manipulate that .xap file through the use of javascript in the browser to show and hide user controls based upon java script events.
Is it possible to do this?
If so any sample could or links to documentation would be appreciated.
Thanks in advance
Kevin
Here's my solution...not sure if it's the "best-practices" way...comments????
In the App class within my Silverlight application I have the following code:
private Page _page = null;
private void Application_Startup(object sender, StartupEventArgs e)
{
_page = new Page();
this.RootVisual = _page;
HtmlPage.RegisterScriptableObject("App", this);
}
Also to the App class I add a [ScriptableMember] to be called from JavaScript
[ScriptableMember]
public void ShowTeamSearch(Guid ctxId, Guid teamId)
{
_page.ShowTeamSearcher(ctxId, teamId);
}
The Page class is the default one that get's created within the Silverlight Control project, it really doesn't have any UI or logic, it's just used to swap in/out the views.
Login oLogin;
TeamSearcher oSearcher;
public Page()
{
InitializeComponent();
oLogin = new Login();
oSearcher = new TeamSearcher();
oLogin.Visibility = Visibility;
this.LayoutRoot.Children.Add(oLogin);
}
Also a method is added to show/hide the views...this could/will probably get more advanced/robust with animations etc...but this shows the basic idea:
public void ShowTeamSearcher(Guid ctxId, Guid teamId)
{
oSearcher.UserTeamId = teamId;
oSearcher.UserContextId = ctxId;
LayoutRoot.Children.Remove(oLogin);
LayoutRoot.Children.Add(oSearcher);
}
Then to invoke this in the JavaScript after assigning the id of oXaml to the instance of the silverlight host.
var slControl = document.getElementById('oXaml');
slControl.Content.App.ShowTeamSearch(sessionId, teamId);
This seems to work and isn't all that bad of a solution, but there might be something better...thoughts?
Here is a my collections of my links for this subject.
Javascript communication to
Silverlight 2.0
Silverlight
interoperability
Silverlight
and JavaScript Interop Basics

Resources